Wind and photovoltaic potential in Europe in the context of mid-term energy storage

Both wind and solar irradiance are considered as variable sources of energy. The generated power is dependent on varying weather conditions. In this study, three indicators are introduced: generation power-to-storage day ratio, photovoltaic-to-wind energy ratio, and reliability improvement indicator. The values of the indicators are determined for 5701 points located in Europe. The results have been presented on charts illustrating statistics of the indicators as well as on maps. This study illustrates various aspects of the solar and the wind energy potential in the context of energy storage. The results show that for the majority of locations, the cost of 1 kWh of storage must be up to 3.2 times less than the cost of 1 kW of a photovoltaic system. Also, it should be up to six times less than the unit cost of the wind turbine system at 50 m in order to decrease the system cost, depending on the number of autonomy days. For most of the locations, the nominal power of the photovoltaic system should be significantly lower than the power of the wind turbine if the system is to meet the required reliability. If the reliability of the power supply has to be increased from 95% to 98%, the nominal power of the photovoltaic generator has to be increased, depending on the assumed days of autonomy, between 1.25 and 1.45 times and the power of the wind turbine at 50 m between 1.3 and 2 times for the greater number of locations.